We have compared the effects of different 12-week exercise programs on simple and choice reaction and movement times in persons 61 to 84 years old. One hundred thirty-eight volunteers were randomized to either a control group, a two-day exercise group (two 60-min sessions a week of aerobic exercises), or a two-day physical plus cognitive exercise group (two 60-min sessions a week of aerobic and cognitive exercises). At follow-up, the aerobic and cognitive exercise program was found to have resulted in significant positive effects. Improvements were found in the two-day physical plus cognitive exercise group in all of the reaction parameters, particularly improvement in choice reaction time, which is used in most daily activities. Our results suggest that to improve reaction time values, it is advisable to include cognitive features into a physical exercise routine.